This invention relates to a method for determining the structure of carbohydrates and more particularly to a method for cleaving and reacting oligosaccharides to give bichromophoric derivatives, separating the derivatives and measuring their characteristics using spectrophotometric methods and determining the structure of the derivatives by spectrophotometric methods. The invention also relates to novel laboratory apparatus which can automatically carry out the structural determination of microscale quantities of oligosaccharides and carbohydrates.
The automatic analysis of amino acid content in protein and peptide samples is known and automatic instruments are available commercially to accomplish this task on samples of unknown structure. An example of such a system is Applied Biosystems Model 420A. In this system, a protein sample is deposited on a glass slide, hydrolyzed and "derivatized" using reagents dispensed by the system. The derivatives of the sample are extracted and delivered to the separation system where they are separated in a micro liquid chromatography column. An ultraviolet detector detects each amino acid present and determines its concentration. The data is displayed by a computer or stored for further analysis.
Likewise, an automated system exists for sequencing nucleic acids, and U.S. Pat. No. 4,811,218 discloses such an apparatus. According to that patent, the apparatus makes use of an enzymatic method of sequencing originally developed by Smith. The patent discloses an improved detecting apparatus capable of sequencing more than one clone at a time.
Neither of these instruments is applicable to structural or analytical work involving sugars. Increasing interest in the structure and properties of such compounds has created a demand for sophisticated yet simplified analysis of oligosaccharides and other types of sugars. Unfortunately, oligosaccharide structure is more difficult to determine because it involves ascertaining the structure of the saccharide subunits and their absolute configuration, and finally their anomeric structure.